docs: refresh CURRENT-STATE, ROADMAP, README, DECISIONS for self-serve cutover

Pulls the public docs forward to match the current state of the repo. No
behavior changes — every edit is informational.

- CURRENT-STATE.md: bump date to 2026-05-07; add entries for PR #159 (Diátaxis
  User Guides), #160 (sidebar IA + account redesign), #161 (self-serve Phase 1
  backend), #162 (Phase 2 frontend cutover), #163 (seed users email-verified),
  #164 (open: taxonomy + INTERNAL_TESTER_EMAILS allowlist). Refresh "What's
  In Progress" and "What's Next" to reflect Phase O cutover as the active work.
- 03-DEVELOPMENT-ROADMAP.md: add a "Status as of 2026-05-07" preamble at the
  top so the months-stale historical content underneath is clearly framed as
  historical record. Replace stale "In Progress" rows (PR #114, ConnectWise
  Advanced) with current ones (#164 cutover, external Director-of-Onboarding
  validation calls). Add Phase O cutover checklist as the new near-term
  priority section. Mark search-and-recall complete (shipped via Voyage AI
  embeddings).
- README.md: replace `docker start patherly_postgres` (legacy container name)
  with `docker compose -f docker-compose.dev.yml up -d`. Repath project tree
  from `patherly/` to `resolutionflow/` and add `.ai/` + `scripts/` directories.
  Replace `UI-DESIGN-SYSTEM.md` (superseded) with `DESIGN-SYSTEM.md` in the
  documentation table; add `AGENTS.md`, `PROJECT_CONTEXT.md`, `PRODUCT.md`.
- DECISIONS.md: append entries for the two architectural decisions made today
  — plan taxonomy reconciliation (rename team→enterprise, add starter) and
  the INTERNAL_TESTER_EMAILS allowlist for self-serve soft cutover.
- .env.example: add INTERNAL_TESTER_EMAILS line (user edit, paired with the
  backend allowlist that landed in the prior commit).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.env.example

@@ -7,4 +7,6 @@ GOOGLE_AI_API_KEY=
 STRIPE_SECRET_KEY=sk_test_
 STRIPE_PUBLISHABLE_KEY=pk_test_
 STRIPE_WEBHOOK_SECRET=whsec_
-VITE_STRIPE_PUBLISHABLE_KEY=pk_test_
+VITE_STRIPE_PUBLISHABLE_KEY=pk_test_
+
+INTERNAL_TESTER_EMAILS=internaltest@resolutionflow.com